ES2631359T3 - Use of estetrol as an emergency contraceptive - Google Patents

Abstract

An emergency contraception method in a female mammal comprising the administration of an emergency contraceptive comprising tetrahydroxylated estrogen represented by the general formula (1): ** Formula ** in which R1, R2, R3, R4 are independently a hydrogen atom, a hydroxyl group, an alkoxy group with 1-5 carbon atoms, or a keto group; preferably in which R1, R2, R3, R4 are independently a hydrogen atom, a hydroxyl group or an alkoxy group with 1-5 carbon atoms; wherein each of R5, R6, R7 is a hydroxyl group; and in which no more than 3 of R1, R2, R3, R4 are hydrogen atoms, in an amount effective to inhibit pregnancy in a female mammal, wherein said administration is performed by non-vaginal administration.

Description

Use of estetrol as an emergency contraceptive FIELD OF THE INVENTION

The present invention relates to a new use of a tetrahydroxylated estrogen represented by formula (I); preferably of the medicinal compound known as estetrol (1,3,5 (10) -estratrien-3,15a, 16a, 17p-tetrol), specifically in an emergency contraceptive method.

BACKGROUND OF THE INVENCI6lM

Despite the availability of very effective contraceptive methods, a large number of pregnancies are not planned, for example as a result of lack of access to contraceptives or contraceptive failure (such as leaving the condom).

Emergency contraception (CD), through the use of a drug or device, is an important way to prevent unwanted pregnancy after intercourse. Several approaches to emergency contraception have been described. Although the intrauterine copper device is the most effective EC method usable up to 5 days after the estimated time of ovulation, its widespread use is limited for logistical and medical reasons. In the late 1970s, Yuzpe introduced a regimen that included the combined use of estrogens (0.1 mg ethinylestradiol) and progestogen (0.5 mg levonorgestrel) within 72 hours after sexual intercourse and repeated after 12 hours. The Yuzpe regimen was associated with a high incidence of nausea and vomiting due to the high estrogen content. Since the 1990s, the potential of levonorgestrel (LNG), a synthetic progestogen, has been recognized. It was shown that treatment with 0.75 mg of LNG, repeated after 12 hours or in a single dose of 1.5 mg, before 72 hours after sexual intercourse was associated with a lower rate of side effects and greater efficacy than Yuzpe's regime. However, if it is administered when the luteinizing hormone has already begun to increase (rise in LH), the LNG is ineffective. The progesterone mifepristone receptor modulator (10 mg) offers another option for CD with very low side effects and greater efficacy than the Yuzpe regimen. Also the interval between intercourse and treatment could extend up to 120 hours with mifepristone. Another regimen is the treatment with the progesterone receptor modulator, ulipristal acetate, which is more effective than LNG and can be used up to 120 hours after intercourse.

There remains a need in the art of alternative methods of emergency contraception with reduced side effects, which are effective in preventing unwanted pregnancy after intercourse and which can be administered in a single effective dose, up to 120 hours after intercourse.

The present invention now provides a new emergency contraceptive that overcomes the problems raised above at least partially.

DESCRIPTION OF THE INVENTION

The present invention provides a new emergency contraceptive, comprising estetrol, a natural estrogen, produced by the human fetal liver only during pregnancy. Structurally, estetrol is characterized by the presence of four hydroxyl groups. In the past, estetrol was considered a weak estrogen due to its relatively low affinity with estrogen receptors. However, recent studies in rats showed high oral absorption and bioavailability, which resulted in renewed interest in estetrol. Recent studies support its potential use in applications such as hormone replacement therapy, contraception, prevention of osteoporosis and treatment of breast cancer (see, for example, Coelingh Bennink et a!., In Contraception, 77, 186 -190, 2008; Visser and Coelingh Bennink in J. Ster. Biochem. & Mol Biol., 114, 85-89, 2009 and US 2004/0192620), but never its use in emergency contraception

In one aspect, the present invention thus provides an emergency contraception method in a mammalian female comprising the administration of an emergency contraceptive comprising tetrahydroxylated estrogen represented by the general formula (I):

(I)

Wherein R1, R2, R3, R4 are independently a hydrogen atom, a hydroxyl group, an alkoxy group with 1-5 carbon atoms, or a keto group, preferably wherein R1, R2, R3, R4 are independently a hydrogen atom, a hydroxyl group or an alkoxy group with 1-5 carbon atoms; wherein each of R5, R6, R7 is a hydroxyl group; and in which no more than 3 of R1, R2, R3, R4 are hydrogen atoms, in an amount effective to inhibit pregnancy in a female mammal, wherein said administration is carried out by a non-vaginal route.

In a preferred embodiment, the tetrahydroxylated estrogen comprised in the emergency contraceptive as described herein is estetrol (1,3,5 (10) -estratrien-3,15a, 16a, 17p-tetrol). In a preferred embodiment, the emergency contraceptive described in the present invention comprises a tetrahydroxylated estrogen in a dose between 0.5 and 7 mg / kg.

In another embodiment the emergency contraceptive described in the present invention further comprises an additional active ingredient suitable for preventing pregnancy.

Another aspect of this description provides the use of an emergency contraceptive as shown in the application to prevent ovulation.

Still another aspect of the present description includes the use of an emergency contraceptive as shown herein to prevent pregnancy.

Yet another aspect of the present description encompasses a method to prevent ovulation and / or pregnancy in a mammalian female comprising the administration of the emergency contraceptive as described herein in an amount effective to inhibit ovulation and / or the pregnancy. In accordance with the invention, the administration of the emergency contraceptive as described herein is performed non-vaginally. More preferably, said administration is carried out by means of oral, parenteral, rectal, transcutaneous or topical administration.

In another preferred embodiment of the method described herein, the administration of the emergency contraceptive as described herein is performed in a single dose.

In another preferred embodiment, the administration of the emergency contraceptive as described herein is carried out in a double dosage, for example an interval of 6, 12, 18 or 24 hours,

In a further preferred embodiment, the administration of the emergency contraceptive described herein is performed within 120 hours after intercourse, preferably within 96, 72, 48, 24, 12 hours or less. Yet another aspect of the present invention provides a method of emergency contraception in female mammals, a method comprising oral, parenteral, rectal, transcutaneous or topical administration of a tetrahydroxylated estrogen represented by the general formula (I):

(I)

wherein R1, R2, R3, R4 are independently a hydrogen atom, a hydroxyl group, an alkoxy group with carbon atoms, or a keto group, preferably wherein R1, R2, R3, R4 are independently an atom of hydrogen, a hydroxyl group or an alkoxy group with 1-5 carbon atoms; wherein each of R5, R6, R7 is a hydroxyl group; and in which no more than 3 of R1, R2, R3, R4 are hydrogen atoms, to a female capable of procreation in an amount effective to inhibit pregnancy and in which the method encompasses the administration of a single dose of said estrogen to said subject within 120 hours following sexual intercourse.

Preferably, said pharmaceutical composition comprises estetrol (1,3,5 (10) -estratrien-3,15a, 16a, 17P-tetrol).

In another embodiment, said pharmaceutical composition further comprises an additional active ingredient.

Yet another aspect of the present description encompasses a kit comprising the emergency contraceptive as described herein or the pharmaceutical composition as described herein, and instructions for use.

BRIEF DESCRIPTION OF THE FIGURES

The present invention is illustrated by the following figures to be considered for illustrative purposes only.

Figure 1 provides the mean plasma levels of estetrol (± standard error) of healthy postmenopausal women who received orally a single dose of 1, 10 6 100 mg of estetrol.

Figure 2 provides the percentage change in the mean levels of luteinizing hormone (LH) in postmenopausal women who received a single oral dose of 100 mg estetrol.

Figure 3 provides the percentage change in mean levels of follicle stimulating hormone (FSH) in postmenopausal women who received a single oral dose of 100 mg estetrol.

DETAILED DESCRIPTION OF THE INVENTION

Matter that is not within the scope of the claims is not part of the claimed invention. As used herein, the singular forms "a", "a", "the" and "the" include both singular and plural referents unless the context clearly indicates otherwise.

The terms "comprising", "comprising" and "understanding" as used herein, are synonymous with "include", "includes" or "contain", "contains", and are inclusive or open-ended and do not exclude components, additional elements or procedural steps not indicated When the embodiments refer to "comprising" particular characteristics, elements or stages, it is intended to specifically include embodiments consisting of the listed features, elements or stages.

The recitation of numerical intervals by endpoints includes all the numbers and fractions subsumed within the respective intervals, as well as the indicated endpoints.

The term "around" as used herein when referring to a measurable value such as a parameter, an amount, a time duration, and the like, is intended to encompass variations of +/- 10% or less, preferably + 1-5% or less, more preferably + 1-1% or less, and even more preferably + 1-0.1% or less and from the specified value, to the extent that such variations are appropriate to make in the invention described. It should be understood that the value accompanied by the "around" modifier is also specific and preferably described.

Unless otherwise defined, all terms used in the disclosure of the invention, including the technical and scientific terms, have the meaning commonly understood by an expert in the technical field to which this invention belongs. For further guidance, definitions of the terms used in the description are included to better appreciate the teachings of the present invention.

Throughout this specification, the reference to "one embodiment" or "the embodiment" means that a particular feature, structure or property described in relation to the embodiment is included in at least one embodiment of the present invention. Thus, the mention of the phrases "in one embodiment" or "in the embodiment" in various places throughout this specification does not necessarily refer to the same embodiment, although it may be so. In addition, the particular properties, structures or characteristics may be combined in any suitable manner, as would be apparent to a person skilled in the art from this description, in one or more embodiments. In addition, although some embodiments described herein include some but not other features included in other embodiments, combinations of features of different embodiments are considered within the scope of the invention, and form different embodiments, as would be understood by those skilled in the art, For example, in the following claims, the claimed embodiments can be used in any combination.

The present inventors have found that emergency contraception can be obtained by administering a single dose of a tetrahydroxylated estrogen, preferably estetrol. They have found that estetrol can inhibit ovulation in rats and prevent pregnancy in rabbits. In addition, they have shown that estetrol has an inhibitory effect on gonadotropins (luteinizing hormone and follicle stimulating hormone) in early postmenopausal women who were given orally a single dose of estetrol. In addition, estetrol was shown to have a high oral bioabsorption and a markedly long elimination half-life.

Accordingly, one aspect of the present invention relates to the use of a tetrahydroxylated estrogen, preferably estetrol, as an emergency contraceptive or in an emergency contraceptive method.

"Emergency contraception" is defined here as a treatment aimed at preventing pregnancy after sexual intercourse. In contrast to a normal contraceptive, which is administered daily in a low dose during the ovulation cycle, an emergency contraceptive is usually administered in a single (or double) dose. "Pregnancy" refers in this context to the condition of a female after a fertilized egg has been successfully implanted in the lining of the uterus.

"Estetrol", "1,3,5 (10) -estratrien-3,15a, 16a, 17p-tetror and" E4 "are synonymous and are used interchangeably herein to refer to a natural estrogen produced by the liver fetal humane only during pregnancy Structurally, it is characterized by the presence of four hydroxyl groups, hence its acronym E4 Estetrol has been proposed for hormone replacement therapy, contraception, prevention of osteoporosis and treatment of breast cancer, but never for its use as an emergency contraceptive Estetrol is a so-called "tetrahydroxylated estrogen" and also includes derivatives, such as those represented by the general formula (I):

(I)

wherein R1, R2, R3, R4 are independently a hydrogen atom, a hydroxyl group, an alkoxy group with carbon atoms, or a keto group;

wherein each of R5, R6, R7 is a hydroxyl group;

and in which no more than 3 of R1, R2, R3, R4 are hydrogen atoms.

In a preferred embodiment, said tetrahydroxylated estrogen is estetrol having the following formula (II):

image 1

image2

Given the remarkably high elimination half-life of estetrol, the emergency contraceptive of the present invention can be administered in a single dose. However, the administration of multiple doses is also covered here, for example two doses, taken for example with 12 hours of separation.

When used in humans, good results can be obtained with a single oral dose of between 30 mg and 400 mg, such as between 40 mg and 250 mg, between 40 mg and 200 mg, between 40 mg and 150 mg, between 40 mg and 100 mg, or between 50 mg and 100 mg of tetrahydroxylated estrogen, preferably estetrol.

Alternatively, the single dose of tetrahydroxylated estrogen, preferably estetrol, can be determined in view of the body weight of the subject to which it should be administered. Typical doses are as follows: 0.5 to 7.0 mg / kg, 1.0 to 5.0 mg / kg, 1.5 to 2.5 mg / kg, or approximately 2.0 mg / kg. Therefore, a dose of 0.5 mg / kg corresponds to

a dose of 30 mg for a subject with a body weight of 60 kg, while a dose of 4 mg / kg corresponds to a dose of 240 mg for a subject with a body weight of 60 kg, etc.

In a preferred embodiment, the emergency contraceptive of the present invention can be administered orally for use as an emergency contraceptive. Advantageously, the inventors have found that after the oral intake a high and rapid peak of estetrol is observed in the plasma. Therefore, immediate effects can be obtained after oral administration of estetrol. Oral dosage forms are well known to those skilled in the art and may be, for example, tablets, film-coated tablets, coated tablets, capsules, gel capsules, pills or powder preparations. In addition to the active ingredient estetrol, the dosage forms according to the present invention further comprise a pharmaceutically acceptable excipient such as, for example, but not limited to, lactose, starch, polyvinylpyrrolidone (PVP), magnesium stearate, etc.

Alternatively, the emergency contraceptive of the present invention can also be administered parenterally, rectally, transcutaneously or topically. According to the invention, the emergency contraceptive of the present invention is administered non-vaginally. In another embodiment, the emergency contraceptive of the present invention can also be administered parenterally, rectally, transcutaneously or topically.

Also described herein are dosage forms that further comprise another active ingredient or an excipient that has a certain activity.

Another aspect of the present description refers to a pharmaceutical composition comprising between 0.5 mg / kg and 7 mg / kg of estetrol, as an active ingredient and a pharmaceutically acceptable excipient.

The emergency contraceptive of the present invention is administered within a limited period of time after sexual intercourse and preferably as soon as possible after sexual intercourse. Usually, this period of time is before 120 hours (5 days) of intercourse, for example before 96 (4 days), 72 (3 days), 48 (2 days), 24 hours (1 day) from sex, or less

The results obtained by the present invention indicate that E4 prevents pregnancies in rabbits with high efficacy. Without wanting to be limited by any theory, E4 can be used up to 120 hours after intercourse, which provides an advantage over known emergency pills. Stetrol has been shown to prevent ovulation and prevent pregnancy. Stetrol is effective even when it is administered shortly before ovulation when the LH peak has already started to rise, a period of time where the use of, for example, levonorgestrel is no longer effective, or even after ovulation, when None of the existing emergency pills is effective.

The inventors have shown that single doses of up to 100 mg of tetrahydroxylated estrogen, preferably estetrol, are safe and well tolerated in humans, which is an advantage over synthetic estrogens such as ethinyl estradiol, which are associated with undesirable side effects such as thromboembolism. , fluid retention, nausea, swelling, cholelithiasis, headache and chest pain.

Another aspect of the present invention relates to an emergency contraception method, a method comprising oral administration of a single dose of tetrahydroxylated estrogen, preferably a stetrol of between 0.5 and 7 mg / kg to a female within 120 hours after sex.

A dosage regimen for emergency contraception using tetrahydroxylated estrogen, preferably estetrol as an active ingredient, is further described herein. The dosage regimen according to the present invention is that a single dose of between 0.5 and 7 mg / kg of tetrahydroxylated estrogen is administered, preferably estetrol as an active ingredient within 120 hours after sexual intercourse.

Alternatively, said dosing regimen can be applied in two consecutive phases, with for example an interval of 6, 12, 18 or 24 hours.

Also described here is an emergency contraceptive kit comprising a pharmaceutical composition comprising tetrahydroxylated estrogen, preferably estetrol as defined herein. The kit may also include instructions for use,

The present invention is further illustrated by the following examples.

EXAMPLES

Example 1 Anti-ovulatory effect of E4 in rats with four-day cycles

The present example demonstrates the antiovulatory activity of estetrol (E4) after oral administration in rats with four-day cycles.

Vaginal smears were obtained from female rats daily for two weeks before the start of treatment to identify rats with four-day cycles. All treatments were administered orally twice a day at approximately 6:30 a.m. and at 4:30 p.m. for four consecutive days (Days 1 * 4), beginning on estrus day. One day after the final dose (Day 5), the rats were euthanized by CO2 asphyxiation at approximately 1:00 p.m., and the number of ovules was counted per oviduct by visualization under a dissecting microscope.

In one study, animals (8 per group) were treated with E4 (0.03; 0.1; 0.3; 1.0 6 3.0 mg / kg) or ethinyl estradiol (EE) (0.0003; 0.001; 0.003; 0.01 6 0.03 mg / kg). The control group received only the vehicle.

All rats ovulated when treated orally with the vehicle while animals that received E4 or EE showed a decrease in ovulatory activity. Treatment with E4 in two daily doses of 0.03 mg / kg did not inhibit ovulation. At higher doses, E4 blocked ovulation in a dose-related manner. Ovulation was inhibited in 2 of 8 rats with two daily doses of E4 of 0.1 mg / kg; In 5 of 8 rats at 0.3 mg / kg; In 7 of 8 rats at 1.0 mg / kg and in 8 of 8 rats at 3.0 mg / kg. The calculated ED50 was 0.182 mg / kg. The twice-daily treatment with EE produced the following responses: 0.0003 mg / kg and 0.001 mg / kg did not inhibit ovulation; 0.003 mg / kg blocked ovulation in 1 of 8 rats; 0.01 mg / kg in 4 of 8 rats; and 0.03 mg / kg in 8 of 8 rats. The calculated ED was 0.01 mg / kg,

The results of this study show that E4, as well as EE, shows an antiovulatory activity under these experimental conditions.

In another study, the antiovulatory activity of E4 was evaluated in relation to that of estradiol (E2). Animals (8 per group) were treated with E4, E2 or vehicle (control group). Due to the inclination of the dose-response curve, the anti-ovulatory EDso for E2 could not be calculated, but was found to be in the range from 0.03 to 0.1 mg / kg. The antiovulatory EDso for E4 was estimated as 0.204 mg / kg.

The results of this study show that both E4, as well as E2, show an antiovulatory activity under these experimental conditions.

In conclusion, studies showed that E4 suppressed ovulation when administered orally to adult cyclic rats.

Example 2: Preventing pregnancy in rabbits

In the present example, it was evaluated whether E4 can prevent pregnancy in rabbits

Eighteen female rabbits tested fertile, 3 per group, were dosed twice daily at intervals of approximately 12 hours for 14 days beginning four days before mating:

Group 1: vehicle control (ASV: 0.9% sodium chloride, 0.4% polysorbate 80, 0.5% carboxymethylcellulose and 0.9% benzyl alcohol in distilled or deionized water, 1 ml / kg)

Group 2: 0.01 mg / kg of E4 in ASV, 1 ml / kg,

Group 3: 0.03 mg / kg of E4 in ASV, 1 ml / kg,

Group 4: 0.1 mg / kg of E4 in ASV, 1 ml / kg,

Team 5; 0.3 mg / kg of E4 in ASV, 1 ml / kg and

Group 6: 1.0 mg / kg of E4 in ASV, 1 ml / kg. The doses were determined by corporate weights returned on the first day of dosing and adjusted according to the weights obtained one week later. Each female rabbit was mated with two male rabbits tested fertile after four days of dosing. The females were necropsied ten days later and the number of pregnancies was determined.

The results of the study are given in Table 1. A total of 25 ovulations were observed in the vehicle control group. Ovulation inhibition was clearly present in the 1.0 mg / kg dose group in which only 3 ovulations were observed. The enlarged uterus in rabbits without luteal bodies confirmed successful copulation. A total of 13 pregnancies resulting from 15 ovulations (2 animals) were observed in the vehicle treated group. At the dose of 0.1 mg / kg no pregnancies were observed, although 20 ovulations occurred. Similarly, at the dose of 0.3 mg / kg, 20 ovulations occurred, but no pregnancies were observed.

Table 1 Effects of vehicle control and different doses of E4 on ovulation and pregnancy

 N luteal bodies N pregnancies

 Individual values (3 animals per group Total number Individual values (3 animals per group Total number

 Vehicle control

 10; 7; 8 25 0; 7; 61 13

 0.01 mg / kg

 13; 92 22 13; 92 22

 0.03 mg / kg

 5; 6; 11 22 5; 5; 11 21

 0.1 mg / kg

 5; 7; 8 20 0; 0.0 0

 0.3 mg / kg

 6; 7; 7 20 0; 0; 0 0

 1.0 mg / kg

 0; 0; 3 3 0; 0; 0 0

 <1> A female in the vehicle control had no pregnancies, <2> A female could not reproduce

It is concluded that oral doses of E4 greater than 0.3 mg / kg (two daily). They induce ovulation inhibition. Dosages above 0.03 mg / kg (two daily) caused the complete prevention of pregnancy

Example 3 Effects of E4 in the pregnancy of the Wistar rat

The objective of the present studies was to evaluate the effects of E «in the pregnancy of the Wistar rat when administered orally by tube,

In one study, groups of seven mated female rats are administered E4 orally, by tube, at dose levels of 30, 60, 6, 90 mg / kg / day from Day 6 to gestation 17 inclusive. A similar group of seven rats was given the vehicle, 0.5% w / v carboxymethyl cellulose, during the same period to act as controls. On the 20th day of pregnancy, the females were examined.

There were no deaths during the study; All animals survived until the scheduled necrapsy. No relevant unexpected clinical observations or findings of necropsy that were considered related to treatment were noted. There was a mean loss of body weight in a group and a marked reduction in the average food intake in all dose groups during the treatment period.

In another study, using the same protocol as in the previous study, E4 is administered to groups of seven paired female rats with dose levels of 0.1.0.3, 1.3 and 10 mg / kg / day or vehicle ( control).

There were no deaths during the study. It was observed that three females of the group receiving 10 mg / kg / day and one female in the group receiving 3 mg / kg / day were hunched towards the end of the gestation period. There were no other clinical observations that were considered related to treatment. With 10 mg / kg / day, there was a general loss in the average body weight during the treatment period, with a reduction in the average food intake. With 0.1, 0.3, 1 and 3 mg / kg / day, the average body weight gains were lower than the controls during the treatment period, with a reduction in the average weight of the uterus recorded in the groups that received 0.3, 1 and 3 mg / kg / day. With 1 and 3 mg / kg / day, the average food intake during the treatment period was slightly lower than the control.

At a dose of less than 3 mg / kg / day, only slight maternal toxicity was observed.

Example 4 Study of toxicity of estetrol in monkeys

A maximum tolerated dose (BAT) study was conducted in adult female cynomolgus monkeys.

Three control animals were treated orally with vehicle and four animals were treated orally with Et as a suspension in vehicle at single doses increasing from 1, 10, 100 to 1000 mg / kg on days 1, 3, 6 and 14 respectively .

There were no unscheduled deaths during the study.

There were no important clinical signs related to treatment with E4. The only adverse clinical sign observed was emesis in an animal treated with E4 at a dose of 1000 mg / kg, approximately 12 hours after dosing.

No effects on body weight or hematological parameters were observed.

Clinical chemistry showed decreased levels of inorganic phosphorus in 2 of 3 control animals and 3 of 4 of the animals treated with 1 mg / kg E <t the day after dosing. Subsequently, decreased levels were observed in all animals treated with E4 after the dose of 100 mg / kg and in a control animal and in all animals treated with E4 after the dose of 1000 mg / kg. This finding is probably minor.

Minor findings were observed in some hepatic parameters (aspartate aminotransferase (AST) and alanine aminotransferase (ALT)) in a control animal and in an animal treated with E4. However, no apparent results related to the object or dose were observed.

Gross autopsy did not reveal unusual findings.

It is concluded that the single oral treatment of cynomolgus monkeys with E4 up to a dose of 1000 mg / kg was well tolerated and did not reveal any relevant toxicological findings.

Example 5: Safety, tolerability, pharmacokinetics and pharmacodynamics of a single dose of E4 in healthy post-menopausal women

In the present example, the safety, tolerability, pharmacokinetics and pharmacodynamics of a single staggered dose of E4 (0.1, 1, 10 and 100 mg) in healthy postmenopausal women were evaluated.

A double-blind, randomized, placebo-controlled study was conducted with a single dose increasing (0.1, 1, 10 and 100 mg of E4) in healthy postmenopausal women. 32 voluntary healthy postmenopausal women between 53 and 69 years of age were recruited. Menopause was defined as> 12 months of amenorrhea or 6 months of amenorrhea with serum levels of FSH 2 40 IU / I and E2 seric <73 pmol / l. The treatment groups were comparable with respect to demographic and characteristic parameters. A total of 8 subjects were assigned to each dose group; six subjects received active treatment and two subjects received placebo,

Security

No serious or severe adverse events were noted. An adverse event was of moderate intensity (back pain, classified as unrelated), all others were mild. A notable adverse event (AE) was reported in a subject of the highest dose group (100 mg Ed): an allergic reaction (hives), which was considered not serious, mild and probably related to E4. The subject recovered completely after several hours. Allergy tests after the study did not confirm a direct allergic response to E4 or the test solution used in the study. The most frequently observed EAs occurred in the classes of the organ system Nervous System Disorders and Gastrointestinal Disorders in subjects in all dosage groups including subjects treated with placebo (see Table 2). The number and nature of AE were similar in subjects with piacebo and in 0.1, 1.0 and 10 mg of E4. The number of AEs (all EAs and related AEs) was higher in subjects with 100 mg of E4. No accumulation of specific EA was observed in any treatment group. The number of subjects who reported AD was comparable in the treatment groups with the lowest number in the 10 mg group, in which only one AE was produced. There were no notable changes in electrocardiograms, in any of the laboratory tests or in vital signs.

Table 2 Adverse drug-related events, reported by more than one subject in any dose group

 Placebo (N = 8) In% 0.1 mg (N = 6) In% 1 mg (N = 6) In% 10 mg (N = 6) In% 100 mg <N = 6) In%

 Gastrointestinal disorders Diarrhea NOS

 1 1 12.5 2 2 33.3

 Musculoskeletal and connective tissue disorders Myalgia

       1 1 16.7 2 2 33.3

 Nervous system disorders Sleepiness

   1 1 16.7 1 1 16.7 2 2 33.3

 N = number of subjects per treatment group E = number of adverse events n = number of subjects with adverse events% = Percentage of subjects with adverse events by number of subjects in treatment group

In conclusion, the results of this study showed that E4 after a single administration at a dose of up to 100 mg is safe and well tolerated.

Pharmacokinetics

The average concentrations of E4 in plasma versus the time graphs of the 1 mg, 10 mg and 100 mg groups are presented in Figure 1. The plasma concentration profiles could not be determined in the 0.1 group subjects. mg

The pharmacokinetic data of E4 were very consistent within each dose group and over the entire dose range studied. The variability between subjects was very low.

The absorption of E4 was extremely rapid and followed by rapid redistribution. The reabsorption was evident during the first 18 hours after oral intake. The compound was removed with a terminal half-life of 28 hours (ranges of 18-60 h).

AUCo-- values were proportional to the oral dose in the range of 10 to 100 mg of E4.

Cmax values were proportional in the range of 1 to 100 mg of E4. The terminal half-life and fractional separation values were not affected by the dose level.

In conclusion, the results of the present study show that, in the dose range tested, E4 has a high oral dose proportional bioabsorption with a consistent plasma profile due to low interindividual variation and a remarkably long terminal elimination half-life of approximately 28 hours

Pharmacodynamics

The pharmacodynamic data showed a clear dose-dependent inhibition of plasma LH levels by E4 up to 48 hours after dosing. The maximum mean suppression was 48% at 4 hours after dosing. A second minimum LH of 45% is observed at 12 hours after dosing, synchronous with the average levels of E4. The percentage change in LH levels of the 100 mg group is shown in Figure 2.

A deep and sustained inhibition of FSH levels could also be established, with a maximum suppression of 41% at 48 hours after dosing, in the 100 mg dose group (not measured in the other groups of

dosage) up to 168 hours (1 week) after dosing. The percentage change in FSH levels of the 100 mg dose group is presented in Figure 3.

Some rapid reaction parameters sensitive to estrogens related to liver metabolism and 6seo in the 100 mg dose group alone were determined. A slight increase in triglycerides and a slight decrease in LDL cholesterol and apolipoprotein-B100 were observed. Minimal changes were observed in osteocalcin and C-telopeptide bone parameters. No relevant changes were observed in the coagulation parameters Factor XII and plasminogen. A slight increase in SHBG and CBG was observed. The general profile suggests a minimal effect on liver metabolism. The interpretation of the pharmacodynamic data should be done carefully taking into account the small number of subjects and the administration of a single dose.

There was no significant endometrial stimulation since none of the subjects experienced withdrawal withdrawal after interruption of progestagen post-treatment.

In conclusion, the effects of E4 on the levels of LH and FSH indicate a strong potency of the compound in the inhibition of central gonadotropin.

Example 6 Study of estetrol ovulation inhibition in healthy women with a regular menstrual cycle

The present example shows the inhibition of ovulation with a single dose of estetrol after oral administration in healthy women with a regular menstrual cycle.

A randomized, double-blind, placebo-controlled, randomized study is conducted in healthy women with a regular menstrual cycle. Women do not use a hormonal contraceptive and a regular menstrual cycle is defined as a menstrual cycle between 24-35 days. Women are randomly assigned to one of the treatment groups, a total of 20 women are assigned to each treatment group. In each treatment group, each woman receives an oral dose of estetrol (for example, 50 mg, 75 mg or 100 mg of estetrol) in one treatment cycle and one oral dose of placebo in another treatment cycle (crossover),

Subjects are first examined in a pretreatment cycle (i.e., a normal menstrual cycle) to investigate follicle development and to confirm ovulation. Follicular development and the endometrium are measured by transvaginal ultrasound (TVUS) every 3 days from day 6 of the menstrual cycle until ovulation is observed. When a 13 mm follicular diameter is measured, subjects are seen every day or every second day. It is considered that an ovulation is confirmed if a value of seric progesterone (P)> 16 nmol / l is measured. The lutea phase must be at least 10 days.

In a treatment cycle, follicular development and the endometrium are measured by TVUS every 3 days from day 6 of the menstrual cycle until the main follicle is £ 18 mm. When a 13 mm follicular diameter is measured, subjects are seen every day 0 every second day. Subjects are treated (with a single oral dose of estetrol or placebo) when the main follicle is £ 18 mm. After treatment, the subject is followed for 6 days by daily TVUS and by blood sample collection to measure hormone levels (FSH, LH, E2, P). In the event that the follicle has already been broken, the subject is still treated.

Example 7 Efficacy, safety and tolerability of estetrol compared with levonorgestrel for emergency contraception in healthy women of reproductive age

The present example shows the efficacy, safety and tolerability of estetrol compared with levonorgestrel (LNG) for emergency contraception in healthy women of reproductive age.

A prospective, randomized, double-blind, multicenter, and active-controlled study is conducted in healthy women of reproductive age with a regular menstrual cycle presented for emergency contraception within 48 to 120 hours after an unprotected sexual relationship, Women are at least 18 years old, do not use hormonal contraception and a regular menstrual cycle is defined as a menstrual cycle between 24-35 days. Women are randomly assigned to receive a one-time treatment with a dose of 50 to 100 mg E4 0 or a dose of 1.5 mg of LNG with follow-up visits at 5 to 48 hours after unprotected sex -7 days after the expected start of menstruation and another visit 12-14 days after the expected start of menstruation (if necessary). 40-45 women per clinical site participate in the study, with a total of 40-45 clinical sites.

Post-treatment pregnancy rates are compared between treatment groups. Pregnancy (efficacy) is detected by detecting the pregnancy hormone human chorionic gonadotropin (hCG) in the serum and the return of menstruation.

Menstrual bleeding patterns are evaluated until follow-up approximately one week after the next menstruation.

Safety and tolerability are assessed by determining routine safety laboratory parameters (hematology, biochemistry and urinalysis), vital signs, performing physical, gynecological and breast exams, blood pressure, heart rate, body weight, and monitoring of serious (serious) adverse events up to e! Follow up approximately one week after the next menstruation.

Claims (12)

1. An emergency contraception method in a female mammal comprising the administration of an emergency contraceptive comprising tetrahydroxylated estrogen represented by the general formula (I): K7 image 1 (I) wherein R1, R2, R3, R4 are independently a hydrogen atom, a hydroxyl group, an alkoxy group with carbon atoms, or a keto group; preferably in which R1, R2, R3, R4 are independently a hydrogen atom, a hydroxyl group or an alkoxy group with 1-5 carbon atoms; wherein each of R5, R6, R7 is a hydroxyl group; Y in which no more than 3 of R1, R2, R3, R4 are hydrogen atoms, in an amount effective to inhibit pregnancy in a female mammal, wherein said administration is performed by a non-vaginal administration. 2. The method according to any one of claim 1, wherein said administration is performed by oral, parenteral, rectal, transcutaneous or topical administration. 3. The method according to any one of claims 1 6 2, wherein said emergency contraceptive further comprises a pharmaceutically acceptable salt or excipient. 4. The method according to any one of claims 1 to 3, wherein said emergency contraceptive further comprises an additional active ingredient suitable for preventing pregnancy. 5. The process according to any one of claims 1 to 4, wherein said tetrahydroxylated estrogen is estetrol (1,3,5 (10) -estratrien-3, 15a, 16a, 17 (3-tetrol). 6. The method according to any one of claims 1 to 5, wherein said emergency contraceptive comprises tetrahydroxylated estrogen in a dose between 0.5 and 7 mg / kg, between 1.0 and 5.0 mg / kg, between 1.5 to 2.5 mg / kg, or approximately 2.0 mg / kg 7. The method according to any one of claims 1 to 5, wherein said emergency contraceptive comprises tetrahydroxylated estrogen in a dose between 30 mg and 400 mg, between 40 mg and 250 mg, between 40 mg and 200 mg, between 40 mg and 150 mg, between 40 mg and 100 mg, between 50 mg and 100 mg, or about 100 mg of estetrol. 8. The method according to any one of claims 1 to 7, wherein the administration is performed in a single dose. 9. The method according to claims 1 to 7, wherein the administration is carried out in a double dosage, for example with an interval of 6, 12, 18 or 24 hours. 10. The method according to any one of claims 1 to 9, wherein said administration is performed within 120 hours after sexual intercourse, preferably within 96 hours, within 72 hours, within 48 hours. hours, within 24 hours, within 12 hours or less. 11. Use of a tetrahydroxylated estrogen represented by the general formula (I): K7 image2 (I) wherein R1, R2, R3, R4 are independently a hydrogen atom, a hydroxyl group, an alkoxy group with carbon atoms, or a keto group; preferably in which R1, R2, R3, R4 are independently a hydrogen atom, a hydroxyl group or an alkoxy group with 1-5 carbon atoms; wherein each of R5, R6, R7 is a hydroxyl group; Y in which no more than 3 of R1, R2, R3, R4 are hydrogen atoms, fifteen as an emergency contraceptive, wherein the administration of said tetrahydroxylated estrogen is carried out by a non-vaginal administration. 12. The use according to claim 11, wherein the administration of said tetrahydroxylated estrogen is carried out by oral, parenteral, rectal, transcutaneous or topical administration.